Practically tasteless quinine com



Patented May 5, 1936 2,039,415

UNITED STATES PATENT OFFICE PRACTIGALLY TASTELESS QUININE COM- POUND ANDPROCESS FOR THE MANU- FACTURE OF SAME Max Hoffer, Basel, Switzerland,assignor to Hofimann-La Roche Inc., Nutley, N. J., a corporation of NewJersey No Drawing.

Application July 25, 1935, Serial No. 33,124. In Germany August 18, 19346 Claims.

It has been found that with quinine and2,3-dlhydroxy-naphthalene-o-mono-acetic acid a difficultly soluble saltmay be obtained, in which the bitter taste of the alkaloid has almostdisappeared.

For the manufacture of the new compound a 195 C., it is tasteless andhas practically no afterwater-soluble quinine salt is allowed to reactwith taste.

a water-soluble salt of 2,3-di-hydroxy-naphtha- I claim:

lene-o-mono-acetic acid in aqueous solution, or 1. The2,3-di-hydroXy-napthhalene-o-monothe quinine base is brought intoreaction with acetate of qui ine, Which crystallizes in needles anequivalent quantity of the acid in a suitable t ng a 3-, the newOOmPOUHd being solvent. ficultly soluble in water, rather difficultlysoluble The 2,3-di-hydroxy-naphthalene-o-mono-acein alcohol and havingpractically no taste. tate of quinine crystallizes in needles melting ate p oc ss o t manufacture of 195 C. It is practically tasteless. Inwater it hydroxy-naphthalene-o-mono-acetate of quinine, is difiicultly,in alcohol rather diflicultly soluble. which comprises allowing one ofthe group It is to be used in medicine. consisting of quinine and itssalts to react with Example one of the group consisting of2,3-di-hydroxynaphthalene-o-mono-acetic acid and its salts.

160 parts by weight of 2,3-di-hydroxy-naphtha- 3. The process for themanufacture of 2,3-dilene are dissolved with 95 parts by weight ofhydroxy-naphthalene-o-mono-acetate of quinine, chloro-acetic acid in 700parts by weight of water which consists in allowing quinine to reactwith on the water-bath. While shaking a solution of2,3-di-hydroXy-naphthalene-o-mono-acetic acid 112 parts by weight ofpotassium hydroxide, disin a solvent. solved in 300 parts by weight ofwater, are added l. The process for the manufacture of 2,3-diwithin anhour. After two hours more the reachydroxy-naphthalene-o-mono-acetate ofquinine, tion product is left to cool, the precipitated crystal whichconsists in allowing the quinine base to repaste removed by suction andwashed with a little act with 2,3-di hydroxy-naphthalene-o-monoalcoholor ether. From the extract unchanged acetic acid in alcoholic solution.2,3-di-hydroxy-naphthalene may be regained. 5. The process for themanufacture of 2,3-di- The potassium salt of2,3-di-hydroXy-naphthahydroXy-naphthalene-o-mono-acetate of quinine,lene-o-mono-acetic acid is warmed with dilute which consists in allowinga quinine salt to react hydrochloric acid. After cooling the free acidis with a Water-soluble salt of 2,3-di-hydroxyprecipitated in longprismatic needles, which melt naphthalene-o-mono-acetic acid in aqueoussoluwith frothing at 157 C. The acid is very easily tion. soluble inalcohol, diflicultly soluble in cold, fairly 6. The process for themanufacture of 2,3-dieasily soluble in warm water.hydroxy-naphthalene-o-mono-acetate of quinine,

To 162 parts by weight of quinine base, diswhich consists in allowingthe quinine base to re-- solved in 600 parts by weight of alcohol 110parts act with 2,3-di-hydroxy-naphthalene-o-monoby weight of2,3-di-hydroxy-naphthalene-oacetic acid in ethyl alcohol solution.mono-acetic acid, dissolved in as little alcohol as possible, are addedwhile stirring and keeping MAX HOFFER.

